This invention relates generally to improvements in bits for drills, and more particularly to an adapter for a conventional flat bit for providing a widened drilled bore or for providing a widened countersunk bore therewith.
Heretofore, attachments have been provided for standard cylindrical bits for widening a drilled bore or providing a countersunk opening thereto. However, such attachments are unknown for flat bladed bits, or such attachments may be known for such bits are unsatisfactory or lack commercial potential.